Explosive compositions



2,982,639 & Patented May 2, 1961 EXPLOSIVE COMPOSITIONS William A. Gey,China Lake, Calif., assignor to the United States of America asrepresented by the Sec- .retary of the Navy The inventiondescribedherein may be manufactured and used by or for the Government ofthe United States of America for governmental purposes without thepaymentof any royalties thereon or therefor.

This invention relates to new explosive compositions; more particularly,it relates to explosive compositions having decreased sensitivity tomechanical shock and which are not sticky.

An objective in the production of high explosives is an explosive whichis relatively insensitive to detonation by mechanical shock and highlysensitive to detonation by explosive shock. A number of explosives whichhave high explosive efiiciency are unsuitable for military or commercialuse because their sensitivity to mechanical shock makes handling of themextremely hazardous. An expedient which has been used to overcome thisdifficulty in a number of explosive compositions is the incorporationtherein of an additive which reduces the sensitivity of the explosive tomechanical shock. For example, paraflin hydrocarbons have been added tosuch explosives as tetranitromethane; nitro aromatic hydrocarbons havebeen added to blasting gelatin; and cellulose acetate has been added tonitroglycerin for the above purpose. A difiiculty attendant to theincorporation of additives in explosive compositions is the fact thatordinarily certain desirable qualities such as brisance, density andothers are sacrificed. Accordingly, this procedure ordinarily results ina compromise between various properties of the explosive.

Petroleum waxes have been used in the past as additives to such highexplosives as cycle trimethylene trinitramine, known in the art as RDX.Although these additives reduce the sensitivity of the explosive tomechanical shock, they also produce a final composition which isexcessively sticky. This latter characteristic makes processingdifiicult. In addition, their incorporation in the explosive results ina lowering of its overall density, thus resulting in a less compactexplosive with resultant loss of explosive power.

It is, therefore, an object of this "invention to provide high explosivecompositions having reduced sensitivity to detonation by mechanicalshock.

It is another object of this invention to provide high explosivecompositions in which sensitivity to-mechanical shock has been loweredby the addition of additives to. high explosives which do notappreciably decrease the explosive power of the explosive and whichproduce final compositions having higher densities than priorcompositions.

It is still another object of this invention to provide high explosivecompositions which are not sticky or tacky and can bereadily processed.

It is a still further object of this invention to provide high explosivecompositions which have good storage characteristics.

It is a further object of this invention to provide a 2 high explosivecomposition which is relatively simple and inexpensive to make.

It has been found that the above and other objects can be accomplishedand the enumerated difliculties overcome .by the incorporation in highexplosives such as cyclotrimethylene trinitramine of ethers of linearmethylene nitramines ormixtures thereof of the structure wherein R isselected from the group consisting of hydrogen, alkyl or alkoxy, =R 'isalkoxy and x is an integer. The above compounds are, prepared by thereaction of the appropriate alcohol with NSX (l-nitroXy-2,4,6-trinitro-2,4,6-triazaheptane), ATX (1,7 dinitroxy-2,4,6-trinitro-2,4,6-triazaheptane), 1-nitroxy-2,4,6-trinitro-2,4,6-triazadecane, 1,9-dinitroxy-2,4,6,8-tetranitro-2,4,6,8-tetrazanonane orother appropriate linear methylene nitramines, as disclosed in theco-pending application entitled Alkyl Ethers of William A. Gey andRobert W. Van Dolah, Serial No. 333,623, filed January 2, 1953, in theUnited States Patent Office. The additives which have been found mosteflfective are the propyl,'butyl, amyl, hexyl and heptyl ethers of NSXand the butyl, amyl, hexyl, heptyl and octyl ethers of ATX.

It has been found that the incorporation of the above type additives inRDX and other explosives increases the density of the compositionWithout appreciable lowering of its explosive power or its sensitivityto explosive shock. In contrast to prior additives, such as petroleumwaxes, the final product is not sticky or tacky so that handling ease isnot affected.

The following examples are illustrative of the invention but are notintended to be limiting thereof.

Example 1 22 grams of RDX were added to a solution of 2.25 grams of theheptyl ether prepared from NSX in 30 cc. of toluene to which had beenadded .1 gram of Span 80. The mixture was slurried in 300 cc. of Waterand heated under agitation until the toluene was steam distilled. Themixture was cooled under agitation to 25 C., filtered and dried. Theresulting composition had a density of 1.625 and an impact sensitivityabout that of commercial composition A.

The procedure of Example 1 was repeated using the hexyl ether of NSX.The product formed from a mixture with this ether had a density of 1.614and an impact sensitivity about that of commercial composition A.

Example 2 4.5 grams of commercial RDX were suspended in 10 cc. ofmethylene chloride containing 0.5 gram of the 1,7-di-n-hexyl etherprepared from ATX. The methylene chloride was removed by boiling in ahot water bath until a paste viscosity remained, then evaporating with avacuum pump. The density of the product when pelleted at 15,000 psi. was1.645 gm. per cc. The impact sensitivity of the compound wasapproximately equal to that of commercialcomposition A (91% RDX-9%petroleum wax).

Example 3 4.50 gms. of RDX were slurried in a solution containing 0.50gram of the 1,7-di-n-octyl ether prepared from ATX in 15 cc. ofmethylene chloride. Most of the methylene chloride was removed byheating in a hot water bath -(-75 C.) until a thick paste remained. Thesuspension was stirred continuously. The remaining methylene chloridewas removed by vacuum. The density of the product was 1.628 gms. per cc.Its impact sensitivity was slightly less than that of commercialcomposition A.

Example 4 A mixture of 18.2 grams of RDX, 1.8 grams of the 1,7-di-n-amylether prepared from ATX and .1 gram of Span were added to 10 grams ofhexane, the resulting mixture warmed and 100 cc. of water added. Thehexane was boiled off with agitation to hold the emulsion. The mixturewas cooled to 30 C., filtered and Washed with .50 cc. of water. Afterair drying for three hours and vacuum desiccation for 40 hours, 19.8grams of product were obtained. Microscopic examination at 75 indicateda complete, homogeneous covering of the particles. The compound wasfound to have an impact sensitivity of 38. (50% shots with a 2 kilo gramweight at 38 centimeters). The compound was found to. have a ballisticmortar value of 138.1% that of TNT. This compares to a ballistic mortarvalue of 130% that of TNT for commercial Composition A. The heat ofexplosion of the compound was 1230 calories per gram. Its densitypressed at 15,000 p.s.i. was 1.661 gms. per cc.

Example 5 A mixture containing of the di-n-hexyl ether prepared from 1,9dinitroxy 2,4,6,8-tetranitro-2,4,6,8- tetrazanonane and 90% RDX byweight was made and tested. The explosive mixture was found to have adensity of 1.592 and an impact sensitivity of 39 using a 2 kg. wt. Thissensitivity is about that of Composition A.

The range of percentage composition of the mixtures is not critical andcan be varied, depending upon the desired characteristics of theproduct, such as sensitivity to mechanical and explosive shock,brisance, density, and other. Obviously, mixtures of the ethers may beused as additives. Although compositions containing cyclotrimethylenetrinitramine have been used to illustrate the invention other highexplosives may be used.

The explosive compositions of the invention are relatively insensitiveto mechanical shock and have higher densities than presently availablecompositions and, therefore, greater explosive power than compositionsmodified with conventional additives. None of the compositions aresticky or tacky so that they can be readily processed.

Obviously many modifications and variations of the present invention arepossible in the light of the above teachings. It is, therefore, to beunderstood that within the scope of the appended claims the inventionmay be practiced otherwise than as specifically described.

What is claimed is:

1. Explosive compositions consisting essentially of approximately 90% byweight of cyclotrimethylene trinitramine and the balance of ethers ofthe structure drogen, lower alkyl, and lower alkoxy, R is lower alkoxyand x is one of the integers 3 and 4, with the limitations that when Ris a hydrogen atom the alkoxy group represented by R has more than 2carbon atoms and when R and R are both alkoxy each of these groups hasmore than 2 carbon atoms.

2. Explosive compositions consisting essentially of approximately byWeight of cyclotrimethylene trinitrarnine, and the balance of ether ofthe formula 3. Explosive compositions consisting essentially ofapproximately 90% by Weight of cyclotrimethylene trinitramine and thebalance of ether of the formula I l H H H 4. Explosive compositionsconsisting essentially of approximately 90% by Weight ofcyclotrimethylene trinitramine and the balance of ether of the formula5. Explosive compositions consisting essentially of approximately 90% byweight of cyclotrimethylene trinitramine and the balance of ether of theformula NO: H NO; 11 NO: H

6. Explosive compositions consisting essentially of approximately 90% byweight of cyclotrimethylene trinitramine and the balance of ether of theformula References Cited in the file of this patent UNITED STATESPATENTS 2,548,880 Fassnatcht et al. Apr. 17, 1951 FOREIGN PATENTS469,721 Germany Dec. 20, 1928 543,174 Germany Feb. 2, 1932 123,252Australia Jan. 23, 1947

1. EXPLOSIVE COMPOSITIONS CONSISTING ESSENTIALLY OF APPROXIMATELY 90% BYWEIGHT OF CYCLOTRIMETHYLENE TRINITRAMINE AND THE BALANCE OF ETHERS OFTHE STRUCTURE